The present invention relates to a subdivided control valve body for injector control valve.
In fuel injection systems for injection of fuel under pressure into the combustion chambers of direct injection internal combustion engines, an injection system with a high pressure collecting chamber (common rail) is utilized. It loads the injector provided for the injection with fuel under high pressure, and its pressure level remains substantially constant. In the injectors, the injection start as well as the fuel quantity injected in the combustion chamber is adjustable. The injector is electrically controlled and mounted on a cylinder head of an internal combustion engine in a space-economical manner.
German patent document DE 197 01 879 A1 discloses a fuel injection device for internal combustion engines. The disclosed fuel injection device for internal combustion engines includes a common high pressure collecting chamber which is fillable from a high pressure pump with fuel (common rail). It is connected through injection lines with injection valves which extend into the combustion chamber of the internal combustion engine to be supplied with fuel. Its opening and closing movements are controlled each by an electrically controlled control valve, wherein the control valve is formed as a 3/2-way valve. It is connected with an injection line or a release line by a high pressure passage which opens to an injection opening of the injection valve. A hydraulic working chamber which is fillable with high pressure fuel is provided on the control member of the control valve. It is controllable for adjusting the adjustment position of the control member of the control valve in a release passage.
The control member used in the 3/2-way control valve in accordance with this solution is formed with a plurality of diameter steps. On the one hand it is therefore difficult to obtain an undisturbed force equalization of the control member, and on the other hand the manufacturing costs are negatively influenced, since several operation steps have to be made on the control valve workpiece during its manufacture.
Accordingly, it is an object of the present invention to provide a valve body for an injector control valve, which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a combustion chamber of an internal combustion engine, comprising an injector housing; a control valve body which is movably received in said injector housing; an actuating unit which activates said control valve body; a restoring element associated with an end side of said control valve body, said control valve body having parts which are held against one another; and a connecting element which holds said parts of said control valve body against one another.
When the control valve is designed in accordance with the present invention, it is easy to manufacture, and with the use of the modular principle and identical parts it can be designed so that a control body can be assembled with two identical parts. The both halves of the inventive control valve body can be held at the end surfaces by clamping elements which engage in the planar position the surfaces which abut against one another.
In accordance with another feature of the present invention which is especially favorable for simple manufacture, the clamping element can be centered on a pin of one half of the inventive control body and fixed. On the other half of the control body the clamping element engages over the end surface and is provided with a radial play with respect to the pin formed on the end surface of this half. With this solution it is guaranteed that the control part halves are not separated in the axial direction on the one hand, and it is possible to radially orient one half of the control body with respect to the other half of the control body in the openings of the control valve housing. In this way manufacturing tolerances can be compensated in an advantageous manner.
In accordance with another advantageous feature of the present invention, the clamping element which holds together the symmetrically constructed halves of the control valve body is accommodated in the region of the control valve housing which is closed from the valve chamber of the control valve. One half of the inventive control body is received in one housing half, while the other half of the control valve body is located in the other housing half of a two-part injector housing. Thereby on the one hand the housing can be separated during mounting in a simple manner, and on another hand the required housing tolerances can be produced in a favorable manner for the manufacture, since the openingxe2x80x94and position tolerances can be compensated by the radial gap between the halves of the control valve.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.